U.S. patent application number 14/506018 was filed with the patent office on 2015-01-22 for hemodialysis and peritoneal dialysis systems having electrodeionization capabilities.
The applicant listed for this patent is Baxter Healthcare S.A., Baxter International Inc., EMD Millipore Corporation. Invention is credited to Yuanpang Samuel Ding, Stephane Dupont, Sujatha Karoor, Ying-Cheng Lo, Joshua James Miller, Justin Rohde.
Application Number | 20150021268 14/506018 |
Document ID | / |
Family ID | 42199053 |
Filed Date | 2015-01-22 |
United States Patent
Application |
20150021268 |
Kind Code |
A1 |
Ding; Yuanpang Samuel ; et
al. |
January 22, 2015 |
HEMODIALYSIS AND PERITONEAL DIALYSIS SYSTEMS HAVING
ELECTRODEIONIZATION CAPABILITIES
Abstract
Systems and methods for hemodialysis or peritoneal dialysis
having integrated electrodeionization capabilities are provided. In
an embodiment, the dialysis system includes a carbon source, a
urease source and an electrodeionization unit. The carbon source
and urease source can be in the form of removable cartridges.
Inventors: |
Ding; Yuanpang Samuel;
(Libertyville, IL) ; Lo; Ying-Cheng; (Green Oaks,
IL) ; Miller; Joshua James; (Wilmette, IL) ;
Rohde; Justin; (Des Plaines, IL) ; Karoor;
Sujatha; (Lake Forest, IL) ; Dupont; Stephane;
(Elancourt, FR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baxter International Inc.
Baxter Healthcare S.A.
EMD Millipore Corporation |
Deerfield
Glattpark (Opfikon)
Billerica |
IL
MA |
US
CH
US |
|
|
Family ID: |
42199053 |
Appl. No.: |
14/506018 |
Filed: |
October 3, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12718609 |
Mar 5, 2010 |
8858792 |
|
|
14506018 |
|
|
|
|
61158101 |
Mar 6, 2009 |
|
|
|
Current U.S.
Class: |
210/638 |
Current CPC
Class: |
A61M 1/284 20140204;
A61M 1/28 20130101; B01D 61/243 20130101; A61M 1/1674 20140204;
A61M 1/287 20130101; A61M 1/1696 20130101; A61M 2202/0014 20130101;
B01D 61/58 20130101; B01D 61/44 20130101 |
Class at
Publication: |
210/638 |
International
Class: |
A61M 1/16 20060101
A61M001/16; A61M 1/28 20060101 A61M001/28 |
Claims
1. A method of performing hemodialysis comprising: passing a spent
dialysis fluid from a dialyzer through a carbon source, a urease
source and an electrodeionization unit to produce a clean dialysis
fluid; and passing the clean dialysis fluid through the
dialyzer.
2. The method of claim 1, which includes passing the clean dialysis
fluid through an ion exchange unit before the clean dialysis fluid
passes through the dialyzer.
3. The method of claim 1, which includes adding at least one
dialysis component to the clean dialysis fluid before the clean
dialysis fluid passes through the dialyzer.
4. A method of performing peritoneal dialysis comprising: passing a
spent dialysis fluid from an individual through a carbon source, a
urease source and an electrodeionization unit to produce a clean
dialysis fluid; and returning the clean dialysis fluid to the
individual.
5. The method of claim 4, which includes passing the clean dialysis
fluid through an ion exchange unit before the clean dialysis fluid
returns to the patient.
6. The method of claim 4, which includes adding at least one
dialysis component to the clean dialysis fluid before the clean
dialysis fluid returns to the individual.
7. The method of claim 4, which includes passing the clean dialysis
fluid through a filter before the clean dialysis fluid returns to
the patient.
8. The method of claim 4, which includes passing the clean dialysis
fluid through an ultraviolet bactericidal light before the clean
dialysis fluid returns to the patient.
9. A method of performing dialysis comprising: passing a spent
dialysis fluid through a dialysis compartment of a dialyzer
comprising an ion-rejection membrane that allows the passage of
negatively charged ions and nonionic species but restricts the
passage of positively charged ions, the ion-rejection membrane
separating the dialysis compartment from a dialysate compartment of
the dialyzer; passing used dialysis fluid generated from the
dialysate compartment of the dialyzer through a carbon source, a
urease source and an electrodeionization unit to produce a clean
dialysis fluid; adding a source of negative ions to the clean
dialysis fluid; and and passing the clean dialysis fluid through
the dialysate compartment of the dialyzer.
10. A method of performing dialysis comprising: passing a spent
dialysis fluid through a dialysis compartment of a dialyzer
comprising an ion-rejection membrane that allows the passage of
positively charged ions and nonionic species but restricts the
passage of negatively charged ions, the ion-rejection membrane
separating the dialysis compartment from a dialysate compartment of
the dialyzer; passing used dialysis fluid generated from the
dialysate compartment of the dialyzer through a carbon source, a
urease source and an electrodeionization unit to produce a clean
dialysis fluid; adding a source of positive ions to the clean
dialysis fluid; and and passing the clean dialysis fluid through
the dialysate compartment of the dialyzer.
Description
PRIORITY CLAIM
[0001] This application is a divisional application of U.S. patent
application Ser. No. 12/718,609, filed Mar. 5, 2010 and claims
priority to and the benefit of U.S. Provisional Patent Application
No. 61/158,101, filed Mar. 6, 2009, the entire content of each of
which is expressly incorporated herein by reference.
BACKGROUND
[0002] The present disclosure generally relates to dialysis
systems. More specifically, the present disclosure relates to
systems and methods for hemodialysis or peritoneal dialysis that
recycle used dialysate through an electrodeionization based
regeneration system. These systems can perform high volume dialysis
treatments without using large volumes of fresh dialysis fluid.
[0003] In both hemodialysis and peritoneal dialysis, two general
classes of dialysis systems currently exist. The first class uses
fresh fluid (e.g., from a solution bag or some sort of water
purification system) to generate dialysis fluid that is used to
dialyze the individual. The second class uses "sorbent" technology
to remove uremic toxins from waste dialysate. Therapeutic agents
such as ions and/or glucose can be injected into the treated
dialysate, which is used to continue the dialysis of the
individual. The main advantage of the sorbent based approach is
that very low volumes of fluid are required to achieve high volume
dialysis treatments.
[0004] Disadvantages of sorbent systems include their high cost,
disposability, and concerns regarding the purity of the recycled
solution, as many ions remain in the fluid after treatment and
verification of purity is technically challenging to perform. For
example, sorbents can have high cartridge costs, insufficient
removal of all of the tap water impurities, and insufficient
removal of all of the uremic toxins in the used dialysate (e.g.,
sulfate). In addition, possible chemicals may be released or
leached from the sorbent cartridge (e.g., zirconium). There may
also be potential issues with pH and sodium balance.
SUMMARY
[0005] The present disclosure relates to systems and methods for
hemodialysis or peritoneal dialysis having integrated
electrodeionization ("EDI") capabilities. The EDI systems and
methods can further be utilized in portable dialysis devices such
as wearable artificial kidneys. In a general embodiment, the
dialysis system includes a carbon source, a urease source, and an
EDI unit. The carbon source and urease source can be in the form of
removable cartridges. The EDI approach maintains the advantage of
low fluid use in a sorbent system, but addresses the key
shortcomings of the sorbent system. The EDI technology is re-usable
over very long periods of time (e.g., 5-7 years) thereby reducing
cost, and essentially removes all ionic contaminants from the waste
dialysate (not just selective ions), resulting in verifiably pure
recycled solution.
[0006] In another embodiment, the disclosure provides a method of
performing hemodialysis. The method comprises passing a spent
dialysis fluid from a dialyzer through a carbon source, a urease
source and an electrodeionization unit to produce a clean dialysis
fluid, and passing the clean dialysis fluid through the dialyzer.
The clean dialysis fluid can pass through an ion exchange unit
before passing through the dialyzer. In addition, one or more
dialysis components can be added to the clean dialysis fluid before
the clean dialysis fluid passes through the dialyzer.
[0007] In an alternative embodiment, the present disclosure
provides a method of performing peritoneal dialysis. The method
comprises passing a spent dialysis fluid from an individual through
a carbon source, a urease source and an electrodeionization unit to
produce a clean dialysis fluid, and returning the clean dialysis
fluid to the individual. The clean dialysis fluid can pass through
an ion exchange unit before returning to the patient. One or more
dialysis components can be added to the clean dialysis fluid before
returning to the individual. The clean dialysis fluid can also pass
through a filter or an ultraviolet bactericidal light returning to
the patient.
[0008] In yet another embodiment, the present disclosure provides a
method of performing dialysis. The method comprises passing a spent
dialysis fluid through a dialysis compartment of a dialyzer
including an ion-rejection membrane that allows the passage of
negatively charged ions and nonionic species but restricts the
passage of positively charged ions. The ion-rejection membrane
separates the dialysis compartment from a dialysate compartment of
the dialyzer. The method further comprises passing used dialysis
fluid generated from the dialysate compartment of the dialyzer
through a carbon source, a urease source and an EDI unit to produce
a clean dialysis fluid. A source containing any desired negative
ions is then added to the clean dialysis fluid. The clean dialysis
fluid passes through the dialysate compartment of the dialyzer.
[0009] In an alternative embodiment, the ion-rejection membrane
allows the passage of positively charged ions and nonionic species
but restricts the passage of negatively charged ions. In this
regard, a source containing any desired positive ions is then added
to the clean dialysis fluid.
[0010] An advantage of the present disclosure is to provide an
improved hemodialysis system.
[0011] Another advantage of the present disclosure is to provide an
improved peritoneal dialysis system.
[0012] Yet another advantage of the present disclosure is to
provide a dialysis system that has a high purity of recycled
dialysis fluid.
[0013] Still another advantage of the present disclosure a dialysis
system having low operating costs.
[0014] Additional features and advantages are described herein, and
will be apparent from, the following Detailed Description and the
figures.
BRIEF DESCRIPTION OF THE FIGURES
[0015] FIG. 1 illustrates a schematic of a dialysis fluid recycling
system for hemodialysis in an embodiment of the present
disclosure.
[0016] FIG. 2 illustrates a schematic of a dialysis fluid recycling
system for peritoneal dialysis in an embodiment of the present
disclosure.
[0017] FIG. 3 illustrates a schematic of a dialysis fluid recycling
system in another embodiment of the present disclosure.
[0018] FIG. 4 illustrates a schematic of a dialysis fluid recycling
system for peritoneal dialysis in an embodiment of the present
disclosure.
[0019] FIG. 5 illustrates a schematic of a dialysis fluid recycling
system for peritoneal dialysis in another embodiment of the present
disclosure.
[0020] FIG. 6 is a graph showing the conductivity of a dialysis
solution treated using an EDI unit versus the operating voltage of
the EDI unit.
[0021] FIG. 7 is a graph showing the operating current of an EDI
unit versus the operating voltage of the EDI unit.
DETAILED DESCRIPTION
[0022] The present disclosure relates to systems and methods for
hemodialysis or peritoneal dialysis having integrated EDI
capabilities. In alternative embodiments, the EDI systems and
methods can be utilized and implemented in various hemodialysis and
peritoneal dialysis technologies. Such dialysis systems are
described in U.S. Pat. Nos. 5,244,568, 5,350,357, 5,662,806,
6,592,542 and 7,318,892, which are incorporated herein by
reference. The EDI systems and methods can further be utilized in
portable dialysis devices such as, for example, wearable artificial
kidneys in which an individual may move freely during dialysis.
Portable dialysis devices are described in U.S. Pat. Nos.
6,196,992, 5,873,853 and 5,984,891, which are incorporated herein
by reference. The EDI systems and methods can be used in medical
centers and be implemented with on-site or at-home dialysis
treatments.
[0023] It should be appreciated that the EDI systems discussed
herein differ from electrodialyzers. There are major differences
between electrodialysis and EDI. An electrodialyzer is used to
remove electrolytes from an aqueous feed solution introduced into a
diluate chamber. An example of an electrolyte is NaCl. However, the
level of electrolyte removal is not allowed to go below a certain
limit. If one goes to a lower limit with very few electrolyte-based
ions left in the solution, water splitting occur (also known as
"electrolysis"), and a considerable amount of energy is wasted in
splitting the water. This water splitting is needed for the current
to flow between the electrodes maintained in the elctrodialysis
stack. The proton and the hydroxyl ion resulting from the water
splitting will carry the current. It is to be avoided for a variety
of reasons.
[0024] An electrodeionizer is an electrodialyzer in which the
diluate channel into which the feed solution is introduced is
filled with a bed of mixed ion exchange resin beads. At the top of
the channel where the feed solution is introduced, the electrolytes
present in the feed solution carry the current. Even though the ion
exchange resin beads are there, they do not serve much of a
deionization function. The mixed ion exchange resin beads in the
electrodeionizer enhance the efficiency of removing the
electrolytes from the dialysate solution as well as alleviate the
effects of water splitting as a result of little to no electrolytes
remaining in the solution further down the channel
[0025] In a general embodiment, a dialysis fluid recycling system
10 for hemodialysis is illustrated in FIG. 1. As shown in FIG. 1, a
circuit 12 represents a standard blood circuit for a hemodialysis
machine. Circuit 12 cycles blood from an individual 16 via flow
path 22 through a dialyzer 20 and returns it to the individual's
body via flow path 24. Dialyzer 20 can include a dialysate
compartment and a blood compartment separated by a suitable
membrane. A circuit 14 includes an EDI unit or module 30 in
dialysis fluid recycling system 10. Circuit 14 can also include a
carbon source 40 and a urease source 50 connected to carbon source
40 via flow path 42. Carbon source 40 and urease source 50 can be
in the form of removable cartridges.
[0026] EDI unit 30 can include a central chamber 32, an anion
chamber 34 having an anode 35, and a cation chamber 36 having a
cathode 37. As fluid exiting urease source 50 flows to central
chamber 32 via flow path 44, a potential difference between anode
35 and cathode 37 causes the electrolytes in the fluid in central
chamber 32 to flow into anion chamber 34 and cation chamber 36.
Specifically, negatively charged ions flow into anion chamber 34
while positively charged ions flow into cation chamber 36 where
they are subsequently removed. The treated fluid that passes
through EDI unit 30 exits as part of a treated fluid stream via
flow path 52. A waste fluid stream filled with electrolytes exits
via flow path 54 that can lead to a drain 70.
[0027] EDI unit 30 can also be modified so that a suitable quantity
of fluid can be recirculated around EDI unit 30 via flow path 56.
This reduces the amount of fluid flowing through EDI unit 30 that
would end up as part of the waste fluid stream. As a result, a
higher quantity of fluid exits as the treated fluid stream as
compared to the quantity of treated fluid from an EDI unit without
recirculation.
[0028] During operation, after priming system 10 with an
appropriate amount of fluid (in this case, priming fluid can be any
of, dialysis fluid, sterile bagged water, tap water in its raw
form, tap water purified through standard means such as
deionization and/or reverse osmosis, or a combination therein), the
dialysis solution is recirculated through circuit 14 via flow path
18 in the direction indicated. Used dialysis fluid leaves dialyzer
20 saturated with uremic toxins, as well as normal dialysis fluid
components such as dextrose and ions (e.g., sodium, calcium,
magnesium, etc.). The organic toxins of the fluid, as well as the
lactate or bicarbonate buffer of the solution, are then removed
from the fluid through adsorption onto a carbon surface (e.g.
activated carbon or other appropriate organic neutralizing surface)
of carbon source 40.
[0029] Urea, which is not well removed by carbon, is then exposed
to urease source 50. Urease is an enzymatic catalyst which
facilitates the breakdown of urea into ammonium and ammonia (e.g.,
depending on pH). Urease source 50 can be immobilized on any
suitable surface that allows the passage of a liquid or be a
membrane impregnated with cross-linked urease enzyme crystals.
[0030] The pKa of ammonium ion is 9.25. For efficient removal, the
pH needs to be below neutral. At lower pH's, a greater portion of
ammonia will be in ionized form. Passing it through an optional
cation exchanger will help lower the pH and have better removal of
ammonia. Removal of the ammonium in can also be accomplished within
EDI unit 20.
[0031] After the fluid has passed through urease source 50, all
organic contaminants will have been adsorbed or broken down into
ionic contaminants before entering EDI unit 30. In EDI unit 30,
ions are removed from the fluid through electromagnetic facilitated
transport through cation and anion selective membranes. The fluid
that exits EDI unit 30, in contrast to currently existing sorbent
systems, contains very few ions, e.g., with nominal fluid
resistivity approaching or in excess of 5 M.OMEGA.cm. In this
regard, EDI unit 30 can render the zirconium phosphate layer,
zirconium bicarbonate layer and/or ion exchange layer typically
used for ammonium/ion removal unnecessary.
[0032] After EDI unit 30, ions and/or fluids can be replaced in the
clean fluid stream through the addition of one or more concentrated
dialysis components from a concentrate or fluid metering source 80
via flow path 82. The concentrated dialysis components can include
one or more osmotic agents (e.g., dextrose, icodextrin, glucose
polymers, glucose polymer derivatives, amino acids), buffers (e.g.,
lactate, bicarbonate) and electrolytes (e.g. sodium, potassium,
calcium, magnesium) from a small fluid source. After this addition,
the fluid is compositionally equivalent to fresh dialysis solution
and can be used to remove additional uremic toxins from the
individual's blood stream.
[0033] To further realize the benefits of EDI over existing sorbent
systems, EDI unit 30 would not be expected to be replaced over the
foreseeable lifetime of the hemodialysis systems/devices. Carbon
source 40 and urease source 50 can be replaced at some determined
interval, but these are much lower cost components than sorbent
cartridges and do not negatively impact the economic benefits of
the system.
[0034] In an embodiment shown in FIG. 1, additions can be made to
enhance the functionality and/or safety of the system. For example,
biological purity of system 10 can be assured through replacement
of circuits 12 and 14 after each treatment, along with dialyzer 20.
However, circuits 12 and 14 can also be re-used for multiple
treatments if suitable disinfection and sanitization methods were
undertaken. These can include all currently accepted methods, such
as heat sanitization, chemical sanitization (including ozonation),
addition of ultraviolet ("UV") bactericidal lights, and the
addition of additional dialyzers and/or ultrafilters in the system
with a pore size appropriate for the removal of bacterial and
sub-bacterial contaminants.
[0035] The monitoring of system 10 can be enhanced through the
inclusion of an optional ammonia sensor in the loop after EDI unit
30 to ensure that all ammonia has been removed. Because fluid of
resistance approaching 5 M.OMEGA.cm can be made after passing
through EDI unit 30, an optional conductivity sensor may be used to
assure there is no ammonia versus the traditional approach of using
an ammonia sensor. Finally, one or more optional ion exchanger unit
60 that have low cost and/or high capacity can be used to
supplement EDI unit 30 to improve its performance or reduce its
necessary size. These optional ion exchangers can include a
phosphate removal exchanger with a bicarbonate counter ion to
enhance phosphate removal or a cation exchanger that helps to
remove any remaining ammonia.
[0036] The dialyzers in any embodiments of the present disclosure
can include an ion-rejection membrane that allows the passage of
negatively charged ions and nonionic species but restricts the
passage of positively charged ions. Alternatively, the dialyzers in
any embodiments of the present disclosure can include an
ion-rejection membrane that allows the passage of positively
charged ions and nonionic species but restricts the passage of
negatively charged ions.
[0037] In another embodiment, a dialysis fluid recycling system 110
for peritoneal dialysis is illustrated in FIG. 2. As shown in FIG.
2, a circuit 112 cycles spent dialysis fluid from an individual 116
via flow path 122 through a dialyzer 120 and returns it to the
individual's body via flow path 124. Dialyzer 120 can include a
dialysate compartment and a peritoneal dialysis fluid compartment
separated by a suitable membrane. A circuit 114 includes an EDI
unit 130 in the dialysis fluid recycling system. Fluid from
dialyzer 120 transfers to circuit 114 via flow path 118.
[0038] Circuit 114 can also include a carbon source 140 and a
urease source 150 connected to carbon source 140 via flow path 142.
Circuit 114 can further include an optional ion exchange unit 160
in fluid connection with EDI unit 130 via flow path 152. Flow path
152 can lead directly back to dialyzer 120. Carbon source 140,
urease source 150 and/or ion exchange unit 160 can be in the form
of removable cartridges.
[0039] EDI unit 130 can include a central chamber 132, an anion
chamber 134 having an anode 135, and a cation chamber 136 having a
cathode 137. As fluid flows through central chamber 132 via flow
path 144, a potential difference between anode 135 and cathode 137
causes the electrolytes in the fluid in central chamber to flow
into anion chamber 134 and cation chamber 136. The treated fluid
that passes through EDI unit 130 exits as part of a treated fluid
stream 152 that leads back to dialyzer 120. A waste fluid stream
filled with electrolytes exits via flow path 54 that leads to a
drain 170.
[0040] EDI unit 130 can also be modified so that a suitable
quantity of fluid can be recirculated around EDI unit 130 via flow
path 156. This reduces the amount of fluid flowing through EDI unit
130 that would end up as part of the waste fluid stream.
[0041] System 110 is nearly identical to the hemodialysis system 10
of FIG. 1. However, in this embodiment, the solution being passed
through circuit 112 represents peritoneal dialysis fluid, rather
than individual's 116 own blood. The peritoneal dialysis procedure
can be run, for example, in a "continuous flow" mode, where used
dialysis fluid exits the individual's peritoneum as new fluid
enters it through a dual lumen catheter. The used fluid is passed
through dialyzer 120 where uremic toxins are removed and the waste
fluid is treated just as it would be in hemodialysis. The
composition of a concentrate addition to the fluid stream in flow
path 152 from a concentrate or fluid metering source 180 via flow
path 182 may be specifically tailored for peritoneal dialysis.
[0042] Additions to this type of system, along with those described
for the hemodialysis system, can be included to enhance
effectiveness or safety of the system. In an embodiment, the
typical dialyzer membrane can be replaced with an ion-rejection
membrane that allows the passage of negatively charged ions and
nonionic species, but restricts the passage of positively charged
ions (or vice versa). In this case, the peritoneal dialysis loop
that is recirculating to the individual would be cleared of uremic
toxins (which are neutrally or negatively charged), but the
concentrate addition would not need to include replacement of the
positive ions of the dialysis solution, which enhances the
efficiency of the system.
[0043] In an alternative embodiment, a dialysis fluid recycling
system 210 for hemodialysis or peritoneal dialysis is illustrated
in FIG. 3. As shown in FIG. 3, a circuit 212 cycles fluid from an
individual 216 through a dialyzer 220 and returns it to the
individual's body. A circuit 214 includes an EDI unit or module 230
in the dialysis fluid recycling system.
[0044] Circuit 214 can also include a carbon source 240 and a
urease source 250 connected to carbon source 240 via flow path 242.
Circuit 214 can further include an optional ion exchange unit 260
in fluid connection with EDI unit 230 via flow path 252. Flow path
252 can lead directly back to dialyzer 220. Carbon source 240,
urease source 250 and/or ion exchange unit 260 can be in the form
of removable cartridges.
[0045] EDI unit 230 can include a central chamber 232, an anion
chamber 234 having an anode 235, and a cation chamber 236 having a
cathode 237. As fluid flows through central chamber 232 via flow
path 244, a potential difference between anode 235 and cathode 237
causes the electrolytes in the fluid in central chamber to flow
into anion chamber 234 and cation chamber 236. The treated fluid
that passes through EDI unit 230 exits as part of a treated fluid
stream 252. A waste fluid stream filled with electrolytes exits via
flow path 254 that leads to a drain 270.
[0046] EDI unit 230 can also be modified so that a suitable
quantity of fluid can be recirculated around EDI unit 230 via flow
path 256. This reduces the amount of fluid flowing through EDI unit
230 that would end up as part of the waste fluid stream.
[0047] After leaving EDI unit 230 via flow path 252, one or more
dialysis components from a concentrate or fluid metering source 280
via flow path 282 may be specifically tailored for the specific
type of dialysis performed. An additional purification or treatment
component 290 in the form of a filter or ultraviolet bactericidal
light can be added to circuit 212, as shown in FIG. 3. Fluid
exiting dialyzer 220 via flow path 226 can be further filtered or
subject to a bactericidal light to enhance the bacterial purity of
system 210. The treated fluid can then enter individual 216 via
flow path 224. Purification component 290 can be especially
important to peritoneal dialysis because bacterial contamination is
a significant concern for the treatment.
[0048] In yet another embodiment, a dialysis fluid recycling system
310 for peritoneal dialysis is illustrated in FIG. 4. As shown in
FIG. 4, a circuit 312 cycles blood from an individual 316 through a
circuit 314. In order to perform the peritoneal dialysis treatment
as shown in FIG. 4, flow path 318 of recycling system 310 can be
constructed such that spent dialysis fluid from individual 316 is
sent directly to recycling system 310 without the need for
"dialyzing" the PD fluid. The peritoneal dialysis procedure can be
run, for example, in a "continuous flow" mode.
[0049] Circuit 314 includes an EDI unit or module 330 in the
dialysis fluid recycling system. Circuit 314 can also include a
carbon source 340 and a urease source 350 connected to carbon
source 340 via flow path 342. Circuit 314 can further include an
optional ion exchange unit 360 in fluid connection with EDI unit
330 via flow path 352. Flow path 352 can lead directly back to
dialyzer 320. Carbon source 340, urease source 350 and/or ion
exchange unit 360 can be in the form of removable cartridges.
[0050] EDI unit 330 can include a central chamber 332, an anion
chamber 334 having an anode 335, and a cation chamber 336 having a
cathode 337. As fluid flows through central chamber 332 via flow
path 344, a potential difference between anode 335 and cathode 337
causes the electrolytes in the fluid in central chamber to flow
into anion chamber 334 and cation chamber 336. The treated fluid
that passes through EDI unit 330 exits as part of a treated fluid
stream 352. A waste fluid stream filled with electrolytes exits via
flow path 354 that leads to a drain 370.
[0051] EDI unit 330 can also be modified so that a suitable
quantity of fluid can be recirculated around EDI unit 330 via flow
path 356. This reduces the amount of fluid flowing through EDI unit
330 that would end up as part of the waste fluid stream.
[0052] After leaving EDI unit 330 via flow path 352, one or more
dialysis components from a concentrate or fluid metering source 380
via flow path 382 may be specifically tailored for the type of
dialysis performed. An additional purifying component 390 such as a
filter, UV light, and/or other commonly accepted methods can
optionally be used on the inlet line to the individual's 316
peritoneal cavity to prevent bacterial contamination and also on
the line from the individual back to system 310 (not shown) to
prevent retro-contamination to individual 316. The purified
dialysis solution can be provided to individual 316 via flow path
322.
[0053] In yet another embodiment, a dialysis fluid recycling system
410 for peritoneal dialysis is illustrated in FIG. 5. As shown in
FIG. 5, a circuit 412 cycles dialysis fluid from an individual 416
to via flow path 422 to a three way valve 490. From three-way valve
490, the fluid flows to a circuit 414 via flow path 418 where the
fluid is recycled. System 410 is designed to operate in a standard
peritoneal dialysis therapy mode where fluid is injected, allowed
to dwell, then removed from individual 416. Once the dialysis fluid
has been purified, the dialysis fluid is then sent back to
individual 416 via flow path 418, allowed to dwell, removed,
purified, and repeated. The control of the flow direction can be
accomplished with three-way valve 490 as shown in FIG. 5.
[0054] Circuit 414 includes an EDI unit 430. Circuit 414 can also
include a carbon source 440 and a urease source 450 connected to
carbon source 440 via flow path 442. Circuit 414 can further
include an optional ion exchange unit 460 in fluid connection with
EDI unit 430 via flow path 452. Flow path 552 can lead directly
back to dialyzer 420. Carbon source 440, urease source 450 and/or
ion exchange unit 460 can be in the form of removable cartridges.
After leaving EDI unit 430 via flow path 452, one or more dialysis
components from a concentrate or fluid metering source 480 via flow
path 482 may be specifically tailored for the type of dialysis
performed.
[0055] EDI unit 430 can include a central chamber 432, an anion
chamber 434 having an anode 435, and a cation chamber 436 having a
cathode 437. As fluid flows through central chamber 432 via flow
path 444, a potential difference between anode 435 and cathode 437
causes the electrolytes in the fluid in central chamber to flow
into anion chamber 434 and cation chamber 436. The treated fluid
that passes through EDI unit 430 exits as part of a treated fluid
stream 452. A waste fluid stream filled with electrolytes exits via
flow path 454 that leads to a drain 470.
[0056] EDI unit 430 can also be modified so that a suitable
quantity of fluid can be recirculated around EDI unit 430 via flow
path 456. This reduces the amount of fluid flowing through EDI unit
430 that would end up as part of the waste fluid stream.
[0057] In addition to the modifications described herein, the
dialysis fluid recycling systems can be further enhanced in several
ways. First, the dialysis fluid recycling system can remove nearly
all solutes from the used or spent dialysis solution (including
therapeutically beneficial solutes, which would then need to be
re-added). The dialysis fluid recycling system can also be designed
to allow reduced removal of the active osmotic agent in the
peritoneal dialysis fluid (e.g., glucose or dextrose). The osmotic
reagent can be replaced with a longer acting molecule, such as
glucose microspheres that can be reintroduced into the dialysis
fluid, to maintain the osmotic gradient in the individual.
EXAMPLES
[0058] By way of example and not limitation, the following example
is illustrative of an embodiment of the present disclosure.
Example 1
[0059] Experiments to determine the extent of the electrolyte
removal using an EDI unit were performed. The experiments simulated
EDI treatment of a post-urease dialysate. A peritoneal dialysis
solution was spiked with 3200 ppm of Ammonium Carbonate (2000 ppm
of urea can be converted into 3200 ppm of ammonium carbonate by
urease). In different studies, the dialysis solution was passed
through the EDI unit at a flow rate of 100 mL/min and 200
mL/min.
[0060] A Millipore EDI-15 Cell with a PK Precision VSP-12010 DC
power supply was used as the EDI unit. Conductivity of the dialysis
solution was measured using an Amber Science EC3084 Conductivity
Meter.
[0061] During the experiments, the conductivity of the treated
dialysis solution versus corresponding voltage/current of the EDI
unit was measured. The final conductivity was compared to the
original conductivity of the untreated dialysis solution. A summary
of the results is shown in Table 1 and FIGS. 6 and 7. FIG. 6 shows
the conductivity of a dialysis solution treated using the EDI unit
versus the operating voltage of the EDI unit. FIG. 7 shows the
operating current of the EDI unit versus the operating voltage of
the EDI unit.
TABLE-US-00001 TABLE 1 Dialysate flow Voltage Conductivity rate
(mL/min) (Volts) Current (Ampere) (mS/cm) % Removal 100 0 0 15.9 0
100 20 2.1 8.4 47 100 40 3.6 2.28 86 100 60 4.3 0.48 97 100 80 5.6
0.08 99 200 80 8.6 0.44 97
[0062] As show in Table 1 and FIGS. 6 and 7, a 99% electrolyte
removal from the dialysis solution can be achieved using the EDI
unit. It was also found that the EDI unit can be operated at a
reduced voltage and reduced current to allow a specific percentage
of electrolytes to pass through. This could allow the use of a
smaller size EDI unit for better portability. In this case, the
small amount of residue electrolytes, including ammonium ions, can
be removed by a supplemental ion-exchange resin column down stream
from the EDI unit.
[0063] Aspects of the subject matter described herein may be useful
alone or in combination one or more other aspect described herein.
Without limiting the foregoing description, in a first aspect of
the present disclosure, a dialysis fluid recycling system includes:
a carbon source; a urease source in fluid communication with the
carbon source; and an electrodeionization unit in fluid
communication with the urease source.
[0064] In accordance with a second aspect of the present
disclosure, which may be used in combination with the first aspect,
the dialysis fluid recycling system includes an ion exchange unit
in fluid communication with the electrodeionization unit.
[0065] In accordance with a third aspect of the present disclosure,
which may be used in combination with any one or more of the
preceding aspects, the dialysis fluid recycling system includes a
metering source in fluid communication with the electrodeionization
unit.
[0066] In accordance with a fourth aspect of the present
disclosure, which may be used in combination with any one or more
of the preceding aspects, a hemodialysis system includes: a carbon
source; a urease source in fluid communication with the carbon
source; an electrodeionization unit in fluid communication with the
urease source; and a dialyzer in fluid communication with the
electrodeionization unit.
[0067] In accordance with a fifth aspect of the present disclosure,
which may be used with any one or more of the preceding aspects in
combination with the 4 aspect, the hemodialysis system includes an
ion exchange unit in fluid communication with the dialyzer.
[0068] In accordance with a sixth aspect of the present disclosure,
which may be used with any one or more of the preceding aspects in
combination with the 4 aspect, the hemodialysis system includes a
metering source in fluid communication with the dialyzer.
[0069] In accordance with a seventh aspect of the present
disclosure, which may be used with any one or more of the preceding
aspects in combination with the 4 aspect, the hemodialysis system
includes a filter in fluid communication with the dialyzer.
[0070] In accordance with an eighth aspect of the present
disclosure, which may be used with any one or more of the preceding
aspects in combination with the 4 aspect, the hemodialysis system
includes an ultraviolet bactericidal light in fluid communication
with the dialyzer.
[0071] In accordance with a ninth aspect of the present disclosure,
which may be used in combination with any one or more of aspects 1
to 3, a peritoneal dialysis system includes: a carbon source; a
urease source in fluid communication with the carbon source; and an
electrodeionization unit in fluid communication with the urease
source.
[0072] In accordance with a tenth aspect of the present disclosure,
which may be used with any one or more of aspects 1 to 3 in
combination with aspect 9, the peritoneal dialysis system includes
an ion exchange unit in fluid communication with the
electrodeionization unit.
[0073] In accordance with an eleventh aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 in combination with aspect 9, the peritoneal dialysis system of
Claim 9, which includes a metering source in fluid communication
with the electrodeionization unit.
[0074] In accordance with a twelfth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 in combination with aspect 9, the peritoneal dialysis system of
Claim 9, which includes a filter in fluid communication with the
electrodeionization unit.
[0075] In accordance with a thirteenth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 in combination with aspect 9, the peritoneal dialysis system
includes an ultraviolet bactericidal light in fluid communication
with the electrodeionization unit.
[0076] In accordance with a fourteenth aspect of the present
disclosure, which may be used in combination with any one or more
of aspects 1 to 8, a method of performing hemodialysis includes:
passing a spent dialysis fluid from a dialyzer through a carbon
source, a urease source and an electrodeionization unit to produce
a clean dialysis fluid; and passing the clean dialysis fluid
through the dialyzer.
[0077] In accordance with a fifteenth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
8 in combination with aspect 14, the method includes passing the
clean dialysis fluid through an ion exchange unit before the clean
dialysis fluid passes through the dialyzer.
[0078] In accordance with a sixteenth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
8 in combination with aspect 14, the method includes adding at
least one dialysis component to the clean dialysis fluid before the
clean dialysis fluid passes through the dialyzer.
[0079] In accordance with a seventeenth aspect of the present
disclosure, which may be used in combination with any one or more
of aspects 1 to 3 and 9 to 13, a method of performing peritoneal
dialysis includes: passing a spent dialysis fluid from an
individual through a carbon source, a urease source and an
electrodeionization unit to produce a clean dialysis fluid; and
returning the clean dialysis fluid to the individual.
[0080] In accordance with an eighteenth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 and 9 to 13 in combination with aspect 17, the method includes
passing the clean dialysis fluid through an ion exchange unit
before the clean dialysis fluid returns to the patient.
[0081] In accordance with a nineteenth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 and 9 to 13 in combination with aspect 17, the method includes
adding at least one dialysis component to the clean dialysis fluid
before the clean dialysis fluid returns to the individual.
[0082] In accordance with a twentieth aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 and 9 to 13 in combination with aspect 17, the method includes
passing the clean dialysis fluid through a filter before the clean
dialysis fluid returns to the patient.
[0083] In accordance with a twenty-first aspect of the present
disclosure, which may be used with any one or more of aspects 1 to
3 and 9 to 13 in combination with aspect 17, the method includes
passing the clean dialysis fluid through an ultraviolet
bactericidal light before the clean dialysis fluid returns to the
patient.
[0084] In accordance with a twenty-second aspect of the present
disclosure, which may be used in combination with any one or more
of the preceding aspects, a method of performing dialysis includes:
passing a spent dialysis fluid through a dialysis compartment of a
dialyzer including an ion-rejection membrane that allows the
passage of negatively charged ions and non-ionic species but
restricts the passage of positively charged ions, the ion-rejection
membrane separating the dialysis compartment from a dialysate
compartment of the dialyzer; passing used dialysis fluid generated
from the dialysate compartment of the dialyzer through a carbon
source, a urease source and an electrodeionization unit to produce
a clean dialysis fluid; adding a source of negative ions to the
clean dialysis fluid; and passing the clean dialysis fluid through
the dialysate compartment of the dialyzer.
[0085] In accordance with a twenty-fourth aspect of the present
disclosure, which may be used in combination with any one or more
of the preceding aspects, a method of performing dialysis includes:
passing a spent dialysis fluid through a dialysis compartment of a
dialyzer including an ion-rejection membrane that allows the
passage of positively charged ions and non-ionic species but
restricts the passage of negatively charged ions, the ion-rejection
membrane separating the dialysis compartment from a dialysate
compartment of the dialyzer; passing used dialysis fluid generated
from the dialysate compartment of the dialyzer through a carbon
source, a urease source and an electrodeionization unit to produce
a clean dialysis fluid; adding a source of positive ions to the
clean dialysis fluid; and passing the clean dialysis fluid through
the dialysate compartment of the dialyzer.
[0086] In accordance with a twenty-fifth aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 1 may be used in combination with
any one or more of the preceding hemodialysis aspects.
[0087] In accordance with a twenty-sixth aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 2 may be used in combination with
any one or more of the preceding peritoneal dialysis aspects.
[0088] In accordance with a twenty-seventh aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 3 may be used in combination with
any one or more of the preceding aspects.
[0089] In accordance with a twenty-eighth aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 4 may be used in combination with
any one or more of the preceding peritoneal dialysis aspects.
[0090] In accordance with a twenty-ninth aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 5 may be used in combination with
any one or more of the preceding peritoneal dialysis aspects.
[0091] In accordance with a thirtieth aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 6 may be used in combination with
any one or more of the preceding aspects.
[0092] In accordance with a thirty-first aspect of the present
disclosure, any of the structure and functionality illustrated and
described in connection with FIG. 7 may be used in combination with
any one or more of the preceding aspects.
[0093] It should be understood that various changes and
modifications to the presently preferred embodiments described
herein will be apparent to those skilled in the art. Such changes
and modifications can be made without departing from the spirit and
scope of the present subject matter and without diminishing its
intended advantages. It is therefore intended that such changes and
modifications be covered by the appended claims.
* * * * *